Date of Award

Spring 5-21-2021

Author's School

McKelvey School of Engineering

Author's Department

Biomedical Engineering

Degree Name

Master of Science (MS)

Degree Type



Gastrointestinal cancers remain to be of the most common and deadly cancers worldwide. Early detection and treatments are crucial for reducing mortality and improving patient outcome. Radiation therapy is a non-invasive localized tumor treatment method, and utilizes radiation to kill the cancerous cells and shrink tumors at specific sites. Precise localization at the target tumor site is therefore important before radiation therapy, especially for gastrointestinal tumor sites located in the moving bowel. Currently, invasive endoscopies along with ink tattoos are used for identifying tumor location, which often require sedation and bring much discomfort. Imaging tests, including CT and MRI, play an important role in cancer assessments due to its non-invasive ability for tumor tracking, and is often used in parallel to assists tumor localization and tracking before onset of radiation therapy. In our study, we aimed to develop an imaging contrast agent that can be injected near the tumor site and be identified under MRI/CT imaging for non-invasive tumor localization and tracking. For the delivery system, we chose the themoresponsive polymer PNIPAM, which underdoes phase transition and crosslinks at body temperature after injection. Next, we loaded iron nanoparticles as CT contrast agent into the PNIPAM delivery system, and together they confirmed to be effective in CT visualized tumor tracking. Lastly, we continue to investigate ways to modify classic MRI contrasts into our PNIPAM delivery system for MRI visualized tumor tracking. Together, we have designed a novel polymer-based contrast agent delivery system that has the potential to change the clinical standard and be widely beneficial by providing long-term, reliable, and non-invasive GI tumor tracking. Further studies are warranted to evaluate functional and safely profiles in mice and in patients for translation to the clinic.


English (en)


Abdel Kareem Azab, PhD Department of Radiation Oncology

Committee Members

Hyun Kim, Dinesh Thotala